Process of producing sulfonic acids of the naphthalene series.



i carried out by subjecting to the action of "from poly-sulfonic acids of the naphthalene UNITED STATES PATENT OFFIGE.

AUG-U "i'l VAGT, 0F LEVERKUSEN, NEAR COLOGNE. GERMANY. ASSIGNOR TO FARBEN- FABRIKEN VORM. FRIEDR. BAYER 8' CO., 01? ELBERFELD, GERMANY, A CORPORA- TION OF GERMANY.

IPROCESS OE PRODUCING SULFONIC ACIDS OF THE NTXEHTHALENE SERIES.

No Drawing.

To all (I'll/JIM it may concern lie it'hriown that l Aucus'r VAG'L', doctor oi philosoplrv, chemist, a citizen of the Ger man Empire, residing at Iaiverkusen, near Cologne, Germany, have invented new and useful Improvements in Processes of Producing Sulfonic Acids of the Naphthalene Series, of which the following is a specification.

My invention relates to a new and valuable process for splitting off sul tonic groups series, which process consists in replacing snlfonic groups by hydrogen. This process an electric current solutions of the sulfonic acids in an eicctrolytical cell which is provided with a cathode c. g. a mercury, amalga mated lead or a zinc cathode.

In carrying out my invention, for example I introdiu'e 250 parts of l-naphthytamin- I).8-disult'onic acid, 75 parts 'of NaOll. dissolved in 2.000 parts of Water into a cell which is provided with an amalgamated lead cathode or which contains at the bottom a layer of mercury being the cathode. The anode is an iron plate which is in the anode chamher separated by a diaphragm and containing a 25 per cent. caustic soda lye. While clectrolyzing (3 ampere on 100 square centimeters) the liquid is kept in motion until the reaction is complete. The liquid is acidulated and heated to boiling. One of Specification of Letters Patent.

Application filed December 6, 1911. Serial No. 664,205.

the sult'onic groups is split oft and from the cooling liquid the i-l'iaphthylamin-3-suli'onic acid separates. The process .proceeds in an analogous manner on using the l.+t.S-, 245-, l.2.--l-.t3 naphthylaminor naphthol sultonio acids, etc.

I clain l. The process of splitting ott sulfonic groups from poIy-sulfonic acids of the naphthaleni-i series which comprises subjecting solutions of such acids to the action of an electric current.

2. The process of splitting ot't' sul't'onic groups from polysult'onic acids oi the naphthalene series which comprises whit-cting alkuli solutions of such acids to the action of an electric current.

I). The process of splitting oft sull'onie groups from aromatic poly-sul't'onic acids which comprises subjecting solutions oi such acids to the action of an electric current.

-t. The process of s 'ilitting oli' sulionir s groups from aromatic poly-sultonic Htflti which comprises subjecting alkali soluti ns oi such acids to the action of an electric cur rent.

In testimony whereof I have hereunto set my hand in the presence of two suhscrihing witnesses.

AUGUTT VAGT. in. Witnesses IIELEN Nnrnn, A. Norma. 

